Increased levels and adipose tissue expression of visfatin in morbidly obese women: the relationship with pro-inflammatory cytokines

Assessment of serum and salivary visfatin levels in newly diagnosed patients of type-II DM

Background

Type II diabetes mellitus (T2DM) is a metabolic disorder. It is thought to be an autoinflammatory disease, as inflammatory mediators are associated with the progression of the disease. Visfatin, an adipokine, is linked to insulin resistance.

Aims

We aimed to study serum and salivary visfatin levels, at the time of diagnosis of T2DM, in middle-aged individuals, in the context of other diagnostic parameters like fasting blood sugar (FBS), postprandial blood sugar (PPBS), and glycated haemoglobin A1c (HbA1c).

Materials and Methods

Thirty newly diagnosed T2DM (Group-I, T2DM) patients and 30 healthy nondiabetic individuals (Group-II, health controls [HC]) matched for age and sex were studied. In both the groups, we assessed serum and salivary visfatin levels, and serum high-sensitivity C-reactive protein (hs-CRP) levels. We also compared serum and salivary visfatin levels and serum hs-CRP levels between Group-I and Group-II individuals.

Statistical Analysis

The correlation between the groups was tested using Pearson's correlation. A P- value < 0.001 was considered to be statistically significant. The data was tabulated using software MS Excel and analysed using IBM Statistical Package for the Social Sciences (SPSS) Version 22.0.

Results

A positive correlation with a value of 0.8836 and a P value of 0.001 was noted between serum and salivary visfatin of Group-I.

Conclusion

This is the first study in the Indian scenario to study the serum and salivary visfatin in newly diagnosed T2DM individuals. Serum visfatin and hs-CRP levels increased in T2DM, thus defining the link between visfatin, inflammation and T2DM, but we failed to notice a positive correlation.

Visfatin and Retinol Binding Protein-4 in Young-Onset Type 2 Diabetes Mellitus

Background and Objectives: The prevalence of type 2 diabetes mellitus in adolescents has increased rapidly in recent decades. However, the role of adipokines on pathophysiology in young-onset type 2 diabetes mellitus (YDM) is not clear. In this article, we explored the relationships between the adipokines (visfatin and retinol binding protein 4 (RBP4)) and metabolic syndrome (MetS) components in both YDM and late-onset type 2 diabetes mellitus (ODM). Materials and Methods: There were 36 patients with YDM (23.6 ± 4.8 years) and 36 patients with ODM (54.3 ± 10.1 years) enrolled. Visfatin, RBP4, and MetS components were measured. The relationships between visfatin, RBP4 and MetS components were assessed in YDM and ODM. Results: The visfatin, but not the RPB4 level, was significantly higher in YDM than in ODM. After adjusting for age and body mass index, visfatin was not related to any MetS components except that there was a negative correlation with fasting plasma glucose (FPG). As for RPB4, triglyceride was found to be positively and FPG negatively related to RBP4 in YDM. However, in ODM, the only positive relationship that existed was between RBP4 and diastolic blood pressure. Conclusions: In conclusion, both visfatin and RBP4 had certain roles in diabetes and MetS although their relationships were different in YDM and ODM. Further studies are needed to explore their physiological and pathological effects in glucose metabolism.

The Complex Roles of Adipokines in Polycystic Ovary Syndrome and Endometriosis

Polycystic ovary syndrome (PCOS) and endometriosis are frequent diseases of the female reproductive tract causing high morbidity as they can significantly affect fertility and quality of life. Adipokines are pleiotropic signaling molecules secreted by white or brown adipose tissues with a central role in energy metabolism. More recently, their involvement in PCOS and endometriosis has been demonstrated. In this review article, we provide an update on the role of adipokines in both diseases and summarize previous findings. We also address the results of multi-omics approaches in adipokine research to examine the role of single nucleotide polymorphisms (SNPs) in genes coding for adipokines and their receptors, the secretome of adipocytes and to identify epigenetic alterations of adipokine genes that might be conferred from mother to child. Finally, we address novel data on the role of brown adipose tissue (BAT), which seems to have notable effects on PCOS. For this review, original research articles on adipokine actions in PCOS and endometriosis are considered, which are listed in the PubMed database.

Adipose Tissue Secretion Pattern Influences β-Cell Wellness in the Transition from Obesity to Type 2 Diabetes

The dysregulation of the β-cell functional mass, which is a reduction in the number of β-cells and their ability to secure adequate insulin secretion, represents a key mechanistic factor leading to the onset of type 2 diabetes (T2D). Obesity is recognised as a leading cause of β-cell loss and dysfunction and a risk factor for T2D. The natural history of β-cell failure in obesity-induced T2D can be divided into three steps: (1) β-cell compensatory hyperplasia and insulin hypersecretion, (2) insulin secretory dysfunction, and (3) loss of β-cell mass. Adipose tissue (AT) secretes many hormones/cytokines (adipokines) and fatty acids that can directly influence β-cell function and viability. As this secretory pattern is altered in obese and diabetic patients, it is expected that the cross-talk between AT and pancreatic β-cells could drive the maintenance of the β-cell integrity under physiological conditions and contribute to the reduction in the β-cell functional mass in a dysmetabolic state. In the current review, we summarise the evidence of the ability of the AT secretome to influence each step of β-cell failure, and attempt to draw a timeline of the alterations in the adipokine secretion pattern in the transition from obesity to T2D that reflects the progressive deterioration of the β-cell functional mass.

Changes in adipokine levels and metabolic profiles following bariatric surgery

BACKGROUND

Bariatric surgery is considered to be the most effective treatment option for weight reduction in obese patients. Abdominal obesity is frequently accompanied by metabolic syndrome (MS). Adipokines are cell signaling proteins that have direct impact upon the metabolic homeostasis. The purpose of this analysis was to evaluate the effect of bariatric surgery, including laparoscopic sleeve gastrectomy (LSG) and laparoscopic gastric bypass (LRYGB) on the adipokine levels and metabolic profile as well as MS and status of type 2 diabetes (T2D).

METHODS

We analyzed anthropometric parameters, blood levels of adipokines, vitamins, lipids and inflammatory markers in 30 bariatric surgery patients with obesity of class II or III 1 month before and 1 year after surgery as well as in 60 obese patients from general practice (GP) and 15 patients with normal body mass (control).

RESULTS

The BMI was significantly higher among patients before surgery and GP patients in comparison to control and post-surgery patients. The levels of glucose, cholesterol and LDL-cholesterol, triglyceride and hs-CRP were the highest in patients before surgery but decreased significantly after surgery, while the level of HDL-cholesterol increased after surgery. The levels of adiponectin increased and that of leptin decreased after surgery. The significant difference in the concentration of resistin was revealed between LSG and LRYGB methods. The relationship between resistin and vitamin D was also found. The patients with MS and T2D displayed significantly greater reduction in lipid markers and adipokine levels than the rest of patients.

CONCLUSION

Remarkable changes in levels of adipokines after bariatric surgery appear like increase in adiponectin and decrease in leptin levels. Significant improvement in anthropometric parameters, metabolic and inflammatory markers occurs, suggesting high potential for reduction of metabolic syndrome and risk for type 2 diabetes. We have shown for the first time ever that level of vitamin D may be involved in resistin regulation.

Physiological Changes and Pathological Pain Associated with Sedentary Lifestyle-Induced Body Systems Fat Accumulation and Their Modulation by Physical Exercise

A sedentary lifestyle is associated with overweight/obesity, which involves excessive fat body accumulation, triggering structural and functional changes in tissues, organs, and body systems. Research shows that this fat accumulation is responsible for several comorbidities, including cardiovascular, gastrointestinal, and metabolic dysfunctions, as well as pathological pain behaviors. These health concerns are related to the crosstalk between adipose tissue and body systems, leading to pathophysiological changes to the latter. To deal with these health issues, it has been suggested that physical exercise may reverse part of these obesity-related pathologies by modulating the cross talk between the adipose tissue and body systems. In this context, this review was carried out to provide knowledge about (i) the structural and functional changes in tissues, organs, and body systems from accumulation of fat in obesity, emphasizing the crosstalk between fat and body tissues; (ii) the crosstalk between fat and body tissues triggering pain; and (iii) the effects of physical exercise on body tissues and organs in obese and non-obese subjects, and their impact on pathological pain. This information may help one to better understand this crosstalk and the factors involved, and it could be useful in designing more specific training interventions (according to the nature of the comorbidity).

Achieving blood pressure targets and antihypertensive effects through metabolic surgery in type 2 diabetes patients with hypertension

AIMS

The effect of metabolic surgery compared with that of conventional therapy on target blood pressure (BP)and defined daily dose (DDD) of antihypertensive drugs in type 2 diabetes (T2DM) patients with hypertension remains unclear. This study aimed to investigate the differences in target BP and DDD between metabolic surgery and conventional treatment in T2DM patients with hypertension.

MATERIALS AND METHODS

This was a prospective study of 535 diabetes patients who underwent metabolic surgery (n = 112) and medical treatment (n = 423). Changes in the target BP from baseline to every follow-up were analysed.

RESULTS

Metabolic surgery decreased both office systolic and diastolic BP (DBP) and also significantly reduced ambulatory systolic BP (SBP; 132 ± 2 vs. 119 ± 1 mmHg, p < 0.0001), but not DBP (78 ± 1 vs. 76 ± 1 mmHg, p = 0.177). Patients maintained their SBP at <120 mmHg after 2 years (50% vs. 1.9%, p < 0.0001). Moreover, the rate of achieving the target SBP of 130 and 140 mmHg was also significantly higher in the surgery group, and this started from the initial 6 months after commencing treatment to the end of follow-up. The dosage (DDD: 1.44 ± 0.65 vs. 0.32 ± 0.05, p < 0.001) of antihypertensive medication was significantly decreased after metabolic surgery. Furthermore, metabolic surgery, but not medical treatment, markedly improved the risks of atherosclerotic cardiovascular disease.

CONCLUSIONS

Metabolic surgery can effectively achieve the BP target and reduce the usage of antihypertensive medications as well as improve multiple metabolic dysfunction in T2DM patients with hypertension. This study provides an alternative approach to antagonize the metabolic related hypertension.

Omentin and visfatin in adolescent inpatients with anorexia nervosa; association with symptoms

Anorexia nervosa (AN) is associated with significant weight loss; thus, it is crucial to discern the contribution of hormones produced by adipose tissue. Some of the adipokines have not been sufficiently studied. Therefore, the present study aims to measure serum concentrations of omentin and visfatin, in adolescent inpatients with AN. The correlations between selected adipokines and psychopathological symptoms of AN were also analyzed. Thirty adolescent inpatients with anorexia nervosa and thirty healthy age and height matched girls (CONT) were enrolled in the study. The physical and mental examination, anthropometric and psychometric assessment - Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HDRS), Eating Attitude Test (EAT-26) and Yale-Brown Obsessive-Compulsive Scale (YBOCS), and blood analysis were performed at two-time points - in the malnourished patients (AN T1) and after partial weight recovery (8.30 ± 3.75 weeks) (AN T2). The omentin concentration was not significantly different from the CONT neither in AN T1 nor AN T2. The visfatin level was altered in AN T1 and did not change after partial weight normalization (AN T2). A positive correlation between visfatin and YBOCS was found in AN T2. Visfatin concentrations were decreased in adolescent inpatients suffering from AN in the acute phase of the disease and did not normalize after partial weight restoration. The studies considering visfatin as a biomarker of the acute phase of AN should be continued. Moreover, the visfatin showed association with the obsessive and compulsive symptoms; thus its participation in non-homeostatic regulation of food intake should be investigated in further studies.

Adipocyte and steroidogenic cell cross-talk in polycystic ovary syndrome

BACKGROUND

Metabolic and endocrine alterations in women with polycystic ovary syndrome (PCOS) affect adipose tissue mass and distribution. PCOS is characterised by hyperandrogenism, obesity and adipocyte dysfunction. Hyperandrogenism in PCOS drives dysfunctional adipocyte secretion of potentially harmful adipocytokines. Glucocorticoids and sex-steroids modulate adipocyte development and function. For their part, adipocyte products interact with adrenal and ovarian steroidogenic cells. Currently, the relationship between adipocyte and steroidogenic cells is not clear, and for these reasons, it is important to elucidate the interrelationship between these cells in women with and without PCOS.

OBJECTIVE AND RATIONALE

This comprehensive review aims to assess current knowledge regarding the interrelationship between adipocytes and adrenal and ovarian steroidogenic cells in animal models and humans with or without PCOS.

SEARCH METHODS

We searched for articles published in English and Portuguese in PubMed. Keywords were as follows: polycystic ovary syndrome, steroidogenesis, adrenal glands, theca cells, granulosa cells, adipocytes, adipocytokines, obesity, enzyme activation, and cytochrome P450 enzymes. We expanded the search into the references from the retrieved articles.

OUTCOMES

Glucocorticoids and sex-steroids modulate adipocyte differentiation and function. Dysfunctional adipocyte products play important roles in the metabolic and endocrine pathways in animals and women with PCOS. Most adipokines participate in the regulation of the hypothalamic-pituitary-adrenal and ovarian axes. In animal models of PCOS, hyperinsulinemia and poor fertility are common; various adipokines modulate ovarian steroidogenesis, depending on the species. Women with PCOS secrete unbalanced levels of adipocyte products, characterised by higher levels of leptin and lower levels of adiponectin. Leptin expression positively correlates with body mass index, waist/hip ratio and levels of total cholesterol, triglyceride, luteinising hormone, oestradiol and androgens. Leptin inhibits the production of oestradiol and, in granulosa cells, may modulate 17-hydroxylase and aromatase enzyme activities. Adiponectin levels negatively correlate with fat mass, body mass index, waist-hip ratio, glucose, insulin and triglycerides, and decrease androgen production by altering expression of luteinising hormone receptor, steroidogenic acute regulatory protein, cholesterol-side-chain cleavage enzyme and 17-hydroxylase. Resistin expression positively correlates with body mass index and testosterone, and promotes the expression of 17-hydroxylase enzyme in theca cells. The potential benefits of adipokines in the treatment of women with PCOS require more investigation.

WIDER IMPLICATIONS

The current data regarding the relationship between adipocyte products and steroidogenic cells are conflicting in animals and humans. Polycystic ovary syndrome is an excellent model to investigate the interrelationship among adipocyte and steroidogenic cells. Women with PCOS manifest some pathological conditions associated with hyperandrogenism and adipocyte products. In animals, cross-talk between cells may vary according to species, and the current review suggests opportunities to test new medications to prevent or even reverse several harmful sequelae of PCOS in humans. Further studies are required to investigate the possible therapeutic application of adipokines in women with obese and non-obese PCOS. Meanwhile, when appropriate, metformin use alone, or associated with flutamide, may be considered for therapeutic purposes.

Contributions of white and brown adipose tissues to the circadian regulation of energy metabolism

The term energy metabolism comprises the entirety of chemical processes associated with uptake, conversion, storage, and breakdown of nutrients. All these must be tightly regulated in time and space to ensure metabolic homeostasis in an environment characterized by cycles such as the succession of day and night. Most organisms evolved endogenous circadian clocks to achieve this goal. In mammals, a ubiquitous network of cellular clocks is coordinated by a pacemaker residing in the hypothalamic suprachiasmatic nucleus. Adipocytes harbor their own circadian clocks, and large aspects of adipose physiology are regulated in a circadian manner through transcriptional regulation of clock-controlled genes. White adipose tissue (WAT) stores energy in the form of triglycerides at times of high energy levels that then serve as fuel in times of need. It also functions as an endocrine organ, releasing factors in a circadian manner to regulate food intake and energy turnover in other tissues. Brown adipose tissue (BAT) produces heat through nonshivering thermogenesis, a process also controlled by the circadian clock. We here review how WAT and BAT contribute to the circadian regulation of energy metabolism. We describe how adipose rhythms are regulated by the interplay of systemic signals and local clocks and summarize how adipose-originating circadian factors feed-back on metabolic homeostasis. The role of adipose tissue in the circadian control of metabolism becomes increasingly clear as circadian disruption leads to alterations in adipose tissue regulation, promoting obesity and its sequelae. Stabilizing adipose tissue rhythms, in turn, may help to combat disrupted energy homeostasis and obesity.

Factors Affecting Metabolic Outcomes Post Bariatric Surgery: Role of Adipose Tissue

Obesity is an ever-growing public health crisis, and bariatric surgery (BS) has become a valuable tool in ameliorating obesity, along with comorbid conditions such as diabetes, dyslipidemia and hypertension. BS techniques have come a long way, leading to impressive improvements in the health of the majority of patients. Unfortunately, not every patient responds optimally to BS and there is no method that is sufficient to pre-operatively predict who will receive maximum benefit from this surgical intervention. This review focuses on the adipose tissue characteristics and related parameters that may affect outcomes, as well as the potential influences of insulin resistance, BMI, age, psychologic and genetic factors. Understanding the role of these factors may help predict who will benefit the most from BS.

The regulation of serum resistin levels in metabolically healthy and unhealthy obese individuals

PURPOSE

We have recently demonstrated that absolute counts of circulating proinflammatory monocytes were lower in obese patients without metabolic syndrome (MS) (metabolically healthy obese, MHO) compared with those with MS (metabolically unhealthy obese, MUO), but higher compared with healthy lean controls (MHL). We hypothesized that circulating resistin, a cytokine secreted by white blood cells (WBC), is involved in obesity-related low-grade inflammation. The aim of this study was to (a) determine serum resistin levels among MUO and MHO subjects and (b) investigate the role of circulating WBC subsets as potential determinants of resistin.

METHODS

Study participants were 58 obese (33 MUO, 25 MHO) and 25 MHL individuals. Serum levels of resistin, high-sensitivity C-reactive protein (hsCRP), and absolute counts of circulating WBC subpopulations were determined. Comparisons were sex- and age-adjusted.

RESULTS

Serum resistin levels in MHL were lower compared with those of obese (p = 0.041), but similar to those of MHO (p = 0.856) individuals. Both resistin (p = 0.005) and absolute neutrophil count (NeuA) (p = 0.025) were higher in MUO compared with MHO. The difference in resistin levels between obese and MHL individuals disappeared after adjustment for NeuA. Resistin correlated positively with absolute total monocyte count (p = 0.037) in MHL and with body mass index (BMI) (p = 0.023), hsCRP (p = 0.022), and NeuA (p = 0.044) in obese subjects. Resistin association with ΒΜΙ disappeared after adjustment for hsCRP, while association with hsCRP disappeared after further adjustment for NeuA.

CONCLUSION

Circulating resistin was higher in MUO compared with MHO. The increased secretion of resistin by the greater number of neutrophils in the former may have contributed to this regulation.

NAD+ metabolism: pathophysiologic mechanisms and therapeutic potential

Nicotinamide adenine dinucleotide (NAD+) and its metabolites function as critical regulators to maintain physiologic processes, enabling the plastic cells to adapt to environmental changes including nutrient perturbation, genotoxic factors, circadian disorder, infection, inflammation and xenobiotics. These effects are mainly achieved by the driving effect of NAD+ on metabolic pathways as enzyme cofactors transferring hydrogen in oxidation-reduction reactions. Besides, multiple NAD+-dependent enzymes are involved in physiology either by post-synthesis chemical modification of DNA, RNA and proteins, or releasing second messenger cyclic ADP-ribose (cADPR) and NAADP+. Prolonged disequilibrium of NAD+ metabolism disturbs the physiological functions, resulting in diseases including metabolic diseases, cancer, aging and neurodegeneration disorder. In this review, we summarize recent advances in our understanding of the molecular mechanisms of NAD+-regulated physiological responses to stresses, the contribution of NAD+ deficiency to various diseases via manipulating cellular communication networks and the potential new avenues for therapeutic intervention.

Evaluation of Serum Biomarkers in Patients with Sarcoidosis: Can Visfatin Be a New Biomarker for Sarcoidosis?

OBJECTIVES

Sarcoidosis is a chronic systemic inflammatory disease that affects multiple organ systems. The role of biomarkers in the diagnosis and prognosis of sarcoidosis is increasing. Interest in the role of adipose tissue-mediated inflammation in the pathogenesis of inflammatory diseases has increased in recent years. Visfatin is a proinflammatory adipocytokine that has been studied for several inflammatory diseases such as diabetes mellitus, obesity, and metabolic syndrome. We aimed to assess serum visfatin levels in sarcoidosis and its relationship with other markers of inflammation such as C-reactive protein (CRP), angiotensin-converting enzyme (ACE) and erythrocyte sedimentation rate (ESR).

MATERIALS AND METHODS

We enrolled 59 patients with sarcoidosis and 21 healthy controls and measured plasma levels of visfatin, along with serum CRP, ESR, and ACE using ELISA (enzyme-linked immunosorbent assay) kits (Blue Gene Biotech, Shanghai, China).

RESULTS

Visfatin levels did not differ significantly between the patients and control subjects (29.9±15.8 ng/mL for patients and 23.93±16.73 ng/mL for controls, p=0.15), and there was no correlation between visfatin and serum CRP, ACE, or ESR in patients with sarcoidosis.

CONCLUSION

Visfatin is recently being discussed as a biomarker for inflammatory diseases in several studies, and results are controversial. In our study, no differences were found in the serum levels of visfatin between patients with sarcoidosis and the control group.

[Ghrelin deficiency in patients with type 2 diabetes: the relationships with obesity, adipose tissue dysfunction and glucose variability]

AIM

Ghrelin, a peptide hormone mostly produced by stomach, plays an important role in regulation of feeding behavior, energy balance and glucose homeostasis.

THE AIM

to determine the relationships between fasting serum levels of ghrelin, body composition, adipose tissue endocrine function and glucose variability (GV) in type 2 diabetic subjects with and without obesity.

MATERIALS AND METHODS

We observed 124 individuals with type 2 diabetes, including 42 non - obese subjects and 82 patients with obesity. Thirty non - obese healthy subjects were acted as control. The concentrations of ghrelin, leptin, resistin, and visfatin in the fasting serum were determined by Multiplex analysis. Body composition was assessed with DEXA. The 24-hour and nocturnal GV parameters were derived from continuous glucose monitoring.

RESULTS AND DISCUSSION

Ghrelin levels in patients with diabetes were decreased significantly as compared to control (p.

Visfatin Connection: Present and Future in Osteoarthritis and Osteoporosis

Musculoskeletal pathologies (MSPs) such as osteoarthritis (OA) and osteoporosis (OP), are a set of disorders that cause severe pain, motion difficulties, and even permanent disability. In developed countries, the current incidence of MSPs reaches about one in four adults and keeps escalating as a consequence of aging and sedentarism. Interestingly, OA and OP have been closely related to similar risk factors, including aging, metabolic alterations, and inflammation. Visfatin, an adipokine with an inflammatory and catabolic profile, has been associated with several OA and OP metabolic risk factors, such as obesity, insulin resistance, and type II diabetes. Furthermore, visfatin has been associated with the innate immune receptor toll-like receptor 4 (TLR4), which plays a key role in cartilage and bone inflammatory and catabolic responses. Moreover, visfatin has been related to several OA and OP pathologic features. The aim of this work is to bring together basic and clinical data regarding the common role of visfatin in these pathologies and their major shared risk factors. Finally, we discuss the pitfalls of visfatin as a potential biomarker and therapeutic target in both pathologies.

Implications of altered NAD metabolism in metabolic disorders

Nicotinamide adenine dinucleotide (NAD) is an important coenzyme that participates in various energy metabolism pathways, including glycolysis, β-oxidation, and oxidative phosphorylation. Besides, it is a required cofactor for post-translational modifications such as ADP-ribosylation and deacetylation by poly (ADP-ribose) polymerases (PARPs) and sirtuins, respectively. Thus, NAD regulates energy metabolism, DNA damage repair, gene expression, and stress response through these enzymes. Numerous studies have shown that NAD levels decrease with aging and under disturbed nutrient conditions, such as obesity. Additionally, a decline in NAD levels is closely related to the development of various metabolic disorders, including diabetes and fatty liver disease. In addition, many studies have revealed that administration of NAD precursors, such as nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), efficiently increase NAD levels in various tissues and prevent such metabolic diseases. These NAD precursors are contained in natural foods, such as cow milk, vegetables, and meats. Therefore, altered NAD metabolism can be a practical target for nutritional intervention. Recently, several human clinical trials using NAD precursors have been conducted to investigate the safety, pharmacokinetics, and efficacy against metabolic disorders such as glucose intolerance. In this review, we summarize current knowledge on the implications of NAD metabolism in metabolic diseases and discuss the outcomes of recent human clinical trials.

A pilot study to examine the association between human gut microbiota and the host's central obesity

Background and Aim

Perturbance in the composition of human gut microbiota has been associated with metabolic disorders such as obesity, diabetes mellitus, and insulin resistance. The objectives of this study are to examine the effects of ethnicity, central obesity, and recorded dietary components on potentially influencing the human gut microbiome. We hypothesize that these factors have an influence on the composition of the gut microbiome.

Methods

Subjects of Chinese (n = 14), Malay (n = 10), and Indian (n = 11) ancestry, with a median age of 39 years (range: 22–70 years old), provided stool samples for gut microbiome profiling using 16S rRNA sequencing and completed a dietary questionnaire. The serum samples were assayed for a panel of biomarkers (interleukin‐6, tumor necrosis factor alpha, adiponectin, cleaved cytokeratin 18, lipopolysaccharide‐binding protein, and limulus amebocyte lysate). Central obesity was defined by waist circumference cut‐off values for Asians.

Results

There were no significant differences in Shannon alpha diversity for ethnicity and central obesity and no associations between levels of inflammatory cytokines and obesity. The relative abundances of Anaerofilum (P = 0.02), Gemellaceae (P = 0.02), Streptococcaceae (P = 0.03), and Rikenellaceae (P = 0.04) were significantly lower in the obese group. From principle coordinate analysis, the effects of the intake of fiber and fat/saturated fat were in contrast with each other, with clustering of obese individuals leaning toward fiber.

Conclusion

The study demonstrated that there were differences in the gut microbiome in obese individuals. Certain bacterial taxa were present in lower abundance in the group with central obesity. Fiber and fat/saturated fat diets were not the key determinants of central obesity.

NAD metabolism: Implications in aging and longevity

Nicotinamide adenine dinucleotide (NAD) is an important co-factor involved in numerous physiological processes, including metabolism, post-translational protein modification, and DNA repair. In living organisms, a careful balance between NAD production and degradation serves to regulate NAD levels. Recently, a number of studies have demonstrated that NAD levels decrease with age, and the deterioration of NAD metabolism promotes several aging-associated diseases, including metabolic and neurodegenerative diseases and various cancers. Conversely, the upregulation of NAD metabolism, including dietary supplementation with NAD precursors, has been shown to prevent the decline of NAD and exhibits beneficial effects against aging and aging-associated diseases. In addition, many studies have demonstrated that genetic and/or nutritional activation of NAD metabolism can extend the lifespan of diverse organisms. Collectively, it is clear that NAD metabolism plays important roles in aging and longevity. In this review, we summarize the basic functions of the enzymes involved in NAD synthesis and degradation, as well as the outcomes of their dysregulation in various aging processes. In addition, a particular focus is given on the role of NAD metabolism in the longevity of various organisms, with a discussion of the remaining obstacles in this research field.

Nonalcoholic fatty liver disease in patients with psoriasis: a consequence of systemic inflammatory burden?

Patients with psoriasis are at an increased risk for nonalcoholic fatty liver disease (NAFLD) compared with the general population. However, the pathophysiology underlying this comorbidity and elucidation of effective treatment strategies are unclear. This review provides insights into the possible role of chronic, low-grade inflammation in the pathogenesis of NAFLD in patients with psoriasis. Both conditions are associated with increased levels of proinflammatory adipokines (such as tumour necrosis factor-α and interleukin-6) and hepatokines, and decreased levels of adiponectin, an anti-inflammatory adipokine. This imbalance in inflammatory mediators could result in insulin resistance and, thereby, facilitate the occurrence and progression of NAFLD in a multistep manner. All patients with psoriasis should, therefore, be considered candidates for NAFLD screening and managed accordingly. Given the common aetiology of inflammation between these conditions, it is hypothesized that biological therapies for psoriasis may attenuate the systemic inflammatory process and progression of NAFLD in patients with psoriasis.

The role of adipokines in skeletal muscle inflammation and insulin sensitivity

Background

There is currently an unmet clinical need to develop better pharmacological treatments to improve glucose handling in Type II Diabetes patients with obesity. To this end, determining the effect of obesity-associated adipokines on skeletal muscle insulin sensitivity has emerged as an important area of drug discovery research. This review draws together the data on the functional role of adipokines on skeletal muscle insulin signalling, highlights several understudied novel adipokines and provides a perspective on the direction of future research.

Main body

The adipokines leptin, resistin, visfatin and adiponectin have all been shown to affect skeletal muscle insulin sensitivity by impacting on the activity of components within insulin signalling pathways, affecting GLUT4 translocation and modulating insulin-mediated skeletal muscle glucose uptake. Furthermore, proteomic analysis of the adipose tissue secretome has recently identified several novel adipokines including vaspin, chemerin and pref-1 that are associated with obesity and insulin resistance in humans and functionally impact on insulin signalling pathways. However, predominantly, these functional findings are the result of studies in rodents, with in vitro studies utilising either rat L6 or murine C2C12 myoblasts and/or myotubes. Despite the methodology to isolate and culture human myoblasts and to differentiate them into myotubes being established, the use of human muscle in vitro models for the functional validation of adipokines on skeletal muscle insulin sensitivity is limited.

Conclusion

Understanding the mechanism of action and function of adipokines in mediating insulin sensitivity in skeletal muscle may lead to the development of novel therapeutics for patients with type 2 diabetes. However, to date, studies conducted in human skeletal muscle cells and tissues are limited. Such human in vitro studies should be prioritised in order to reduce the risk of candidate drugs failing in the clinic due to the assumption that rodent skeletal muscle target validation studies will to translate to human.

NAMPT-mediated NAD+ biosynthesis is indispensable for adipose tissue plasticity and development of obesity

Objective

The ability of adipose tissue to expand and contract in response to fluctuations in nutrient availability is essential for the maintenance of whole-body metabolic homeostasis. Given the nutrient scarcity that mammals faced for millions of years, programs involved in this adipose plasticity were likely evolved to be highly efficient in promoting lipid storage. Ironically, this previously advantageous feature may now represent a metabolic liability given the caloric excess of modern society. We speculate that nicotinamide adenine dinucleotide (NAD⁺) biosynthesis exemplifies this concept. Indeed NAD⁺/NADH metabolism in fat tissue has been previously linked with obesity, yet whether it plays a causal role in diet-induced adiposity is unknown. Here we investigated how the NAD⁺ biosynthetic enzyme nicotinamide phosphoribosyltransferase (NAMPT) supports adipose plasticity and the pathological progression to obesity.

Methods

We utilized a newly generated Nampt loss-of-function model to investigate the tissue-specific and systemic metabolic consequences of adipose NAD⁺ deficiency. Energy expenditure, glycemic control, tissue structure, and gene expression were assessed in the contexts of a high dietary fat burden as well as the transition back to normal chow diet.

Results

Fat-specific Nampt knockout (FANKO) mice were completely resistant to high fat diet (HFD)-induced obesity. This was driven in part by reduced food intake. Furthermore, HFD-fed FANKO mice were unable to undergo healthy expansion of adipose tissue mass, and adipose depots were rendered fibrotic with markedly reduced mitochondrial respiratory capacity. Yet, surprisingly, HFD-fed FANKO mice exhibited improved glucose tolerance compared to control littermates. Removing the HFD burden largely reversed adipose fibrosis and dysfunction in FANKO animals whereas the improved glucose tolerance persisted.

Conclusions

These findings indicate that adipose NAMPT plays an essential role in handling dietary lipid to modulate fat tissue plasticity, food intake, and systemic glucose homeostasis.

•

Fat-specific Nampt knockout (FANKO) does not alter body composition on chow diet.

•

NAMPT is essential for adipose expansion and weight gain from high dietary fat.

•

Loss of adipose NAD⁺ decreases food intake and improves glucose tolerance.

•

High fat diet-induced metabolic dysfunction in FANKO mice is reversible.

Oleate ameliorates palmitate-induced reduction of NAMPT activity and NAD levels in primary human hepatocytes and hepatocarcinoma cells

BACKGROUND

Nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide adenine dinucleotide (NAD) levels are crucial for liver function. The saturated fatty acid palmitate and the unsaturated fatty acid oleate are the main free fatty acids in adipose tissue and human diet. We asked how these fatty acids affect cell survival, NAMPT and NAD levels in HepG2 cells and primary human hepatocytes.

METHODS

HepG2 cells were stimulated with palmitate (0.5mM), oleate (1mM) or a combination of both (0.5mM/1mM) as well as nicotinamide mononucleotide (NMN) (0.5 mM) or the specific NAMPT inhibitor FK866 (10nM). Cell survival was measured by WST-1 assay and Annexin V/propidium iodide staining. NAD levels were determined by NAD/NADH Assay or HPLC. Protein and mRNA levels were analysed by Western blot analyses and qPCR, respectively. NAMPT enzyme activity was measured using radiolabelled 14C-nicotinamide. Lipids were stained by Oil red O staining.

RESULTS

Palmitate significantly reduced cell survival and induced apoptosis at physiological doses. NAMPT activity and NAD levels significantly declined after 48h of palmitate. In addition, NAMPT mRNA expression was enhanced which was associated with increased NAMPT release into the supernatant, while intracellular NAMPT protein levels remained stable. Oleate alone did not influence cell viability and NAMPT activity but ameliorated the negative impact of palmitate on cell survival, NAMPT activity and NAD levels, as well as the increased NAMPT mRNA expression and secretion. NMN was able to normalize intracellular NAD levels but did not ameliorate cell viability after co-stimulation with palmitate. FK866, a specific NAMPT inhibitor did not influence lipid accumulation after oleate-treatment.

CONCLUSIONS

Palmitate targets NAMPT activity with a consequent cellular depletion of NAD. Oleate protects from palmitate-induced apoptosis and variation of NAMPT and NAD levels. Palmitate-induced cell stress leads to an increase of NAMPT mRNA and accumulation in the supernatant. However, the proapoptotic action of palmitate seems not to be mediated by decreased NAD levels.

Adipokines in Liver Cirrhosis

Liver fibrosis can progress to cirrhosis, which is considered a serious disease. The Child-Pugh score and the model of end-stage liver disease score have been established to assess residual liver function in patients with liver cirrhosis. The development of portal hypertension contributes to ascites, variceal bleeding and further complications in these patients. A transjugular intrahepatic portosystemic shunt (TIPS) is used to lower portal pressure, which represents a major improvement in the treatment of patients. Adipokines are proteins released from adipose tissue and modulate hepatic fibrogenesis. These proteins affect various biological processes that are involved in liver function, including angiogenesis, vasodilation, inflammation and deposition of extracellular matrix proteins. The best studied adipokines are adiponectin and leptin. Adiponectin protects against hepatic inflammation and fibrogenesis, and leptin functions as a profibrogenic factor. These and other adipokines are supposed to modulate disease severity in patients with liver cirrhosis. Consequently, circulating levels of these proteins have been analyzed to identify associations with parameters of hepatic function, portal hypertension and its associated complications in patients with liver cirrhosis. This review article briefly addresses the role of adipokines in hepatitis and liver fibrosis. Here, studies having analyzed these proteins in systemic blood in cirrhotic patients are listed to identify adipokines that are comparably changed in the different cohorts of patients with liver cirrhosis. Some studies measured these proteins in systemic, hepatic and portal vein blood or after TIPS to specify the tissues contributing to circulating levels of these proteins and the effect of portal hypertension, respectively.

The Effects on Obesity Related Peptides of Laparoscopic Gastric Band Applications in Morbidly Obese Patients

BACKGROUND

The aim of this study was to examine the relationship between weight loss and resistin, apelin, chemerin, and visfatin after laparoscopic adjustable gastric banding (LAGB).

METHODS

The study group consisted of 19 patients who were operated on for morbid obesity (BMI: 48.7 ± 6.6 kg/m²), and 22 healthy, normal-weight (BMI: 22.9 ± 2.5 kg/m²) subjects formed the control group. We obtained blood samples from the study subjects at three different times: before undergoing surgery and at one month and 6 months after surgery. Blood was obtained once from the control group.

RESULTS

Significant weight loss was achieved at one and 6 months after surgery. Plasma levels of apelin, resistin, chemerin, and visfatin were higher in morbidly obese patients compared with the control group. Obesity-related peptides decreased one month and 6 months after surgery.

CONCLUSIONS

Elevated plasma resistin, apelin, chemerin, and visfatin levels in morbidly obese patients are gradually reduced after weight loss. According to these findings, LAGB surgery is found to be an important and efficient means for morbidly obese patients both to lose weight and to develop a better metabolic risk profile in a short time period.

The relationship between circulating visfatin/nicotinamide phosphoribosyltransferase, obesity, inflammation and lipids profile in elderly population, determined by structural equation modeling

BACKGROUND

The available literature suggests that circulating visfatin/Nicotinamide Phosphoribosyltransferase (NAMPT) level variability in humans is related to obesity, insulin resistance, inflammation, and lipid profile. The aim of the study was to assess the relationship between circulating visfatin/NAMPT, obesity, insulin resistance, inflammation, and lipid profile in a large population-based, elderly cohort, applying structural equation modeling.

MATERIALS AND METHODS

The analysis included 2983 elderly participants of the PolSenior study with assessed total blood count, fasting concentrations of lipids, glucose, insulin, hs-CRP, interleukin-6, and visfatin/NAMPT (by ELISA), and calculated HOMA-IR.

RESULTS

The circulating visfatin/NAMPT levels were higher in obese compared to normal weight subjects, in those with hs-CRP above 3 mg/L, with low serum HDL cholesterol, and in insulin resistant subjects. Based on results of the exploratory factor analysis, a baseline model of mutual relationship between four latent and measured variables was created and a final model was developed by maintaining only two significant categories. The important variables for 'latent inflammation' proved to be hs-CRP and IL-6 serum levels. In the case of 'nutritional status', important variables were BMI, waist circumference, and to a lesser extent insulin resistance. Additionally, the residual correlation between those two constructs was also statistically significant.

CONCLUSION

The structural equation modeling provided support for the existence of a link between nutritional status, inflammation and circulating visfatin/NAMPT level. This indicates that circulating visfatin/NAMPT can be considered as a novel surrogate marker of systemic inflammation associated with fat depot, especially visceral, in the elderly population.

Differential Role of Adipose Tissues in Obesity and Related Metabolic and Vascular Complications

This review focuses on the contribution of white, brown, and perivascular adipose tissues to the pathophysiology of obesity and its associated metabolic and vascular complications. Weight gain in obesity generates excess of fat, usually visceral fat, and activates the inflammatory response in the adipocytes and then in other tissues such as liver. Therefore, low systemic inflammation responsible for insulin resistance contributes to atherosclerotic process. Furthermore, an inverse relationship between body mass index and brown adipose tissue activity has been described. For these reasons, in recent years, in order to combat obesity and its related complications, as a complement to conventional treatments, a new insight is focusing on the role of the thermogenic function of brown and perivascular adipose tissues as a promising therapy in humans. These lines of knowledge are focused on the design of new drugs, or other approaches, in order to increase the mass and/or activity of brown adipose tissue or the browning process of beige cells from white adipose tissue. These new treatments may contribute not only to reduce obesity but also to prevent highly prevalent complications such as type 2 diabetes and other vascular alterations, such as hypertension or atherosclerosis.

Multiple Sclerosis and Obesity: Possible Roles of Adipokines

Multiple Sclerosis (MS) is an autoimmune disorder of the Central Nervous System that has been associated with several environmental factors, such as diet and obesity. The possible link between MS and obesity has become more interesting in recent years since the discovery of the remarkable properties of adipose tissue. Once MS is initiated, obesity can contribute to increased disease severity by negatively influencing disease progress and treatment response, but, also, obesity in early life is highly relevant as a susceptibility factor and causally related risk for late MS development. The aim of this review was to discuss recent evidence about the link between obesity, as a chronic inflammatory state, and the pathogenesis of MS as a chronic autoimmune and inflammatory disease. First, we describe the main cells involved in MS pathogenesis, both from neural tissue and from the immune system, and including a new participant, the adipocyte, focusing on their roles in MS. Second, we concentrate on the role of several adipokines that are able to participate in the mediation of the immune response in MS and on the possible cross talk between the latter. Finally, we explore recent therapy that involves the transplantation of adipocyte precursor cells for the treatment of MS.

Does bariatric surgery improve adipose tissue function?

Bariatric surgery is currently the most effective treatment for obesity. Not only do these types of surgeries produce significant weight loss but also they improve insulin sensitivity and whole body metabolic function. The aim of this review is to explore how altered physiology of adipose tissue may contribute to the potent metabolic effects of some of these procedures. This includes specific effects on various fat depots, the function of individual adipocytes and the interaction between adipose tissue and other key metabolic tissues. Besides a dramatic loss of fat mass, bariatric surgery shifts the distribution of fat from visceral to the subcutaneous compartment favoring metabolic improvement. The sensitivity towards lipolysis controlled by insulin and catecholamines is improved, adipokine secretion is altered and local adipose inflammation as well as systemic inflammatory markers decreases. Some of these changes have been shown to be weight loss independent, and novel hypothesis for these effects includes include changes in bile acid metabolism, gut microbiota and central regulation of metabolism. In conclusion bariatric surgery is capable of improving aspects of adipose tissue function and do so in some cases in ways that are not entirely explained by the potent effect of surgery. © 2016 World Obesity.

Increased plasma nicotinamide phosphoribosyltransferase is associated with a hyperproliferative phenotype and restrains disease progression in MPN-associated myelofibrosis

Myeloproliferative neoplasm (MPN)-associated myelofibrosis is a clonal, neoplastic disorder of the hematopoietic stem cells, in which inflammation and immune dysregulation play an important role. Extracellular nicotinamide phosphoribosyltransferase (eNAMPT), also known as visfatin, is a cytokine implicated in a number of inflammatory and neoplastic diseases. Here plasma levels of eNAMPT in patients with MPN-associated myelofibrosis and their effects on disease phenotype and outcomes were examined. The concordance of eNAMPT levels with the marker of general inflammation high-sensitivity C-reactive protein (hs-CRP) was also studied. A total of 333 MPN-associated myelofibrosis patients (187 males and 146 females) and 31 age- and gender-matched normal-weight healthy subjects were enrolled in the study main body. Levels of eNAMPT and hs-CRP were simultaneously assayed in 209 MPN-associated myelofibrosis patients. Twenty-four polycythemia vera or essential thrombocythemia patients were used as controls. eNAMPT was over expressed in MPN-associated myelofibrosis, and eNAMPT expression was correlated with higher white blood cell count, higher hemoglobin, and higher platelet count, suggesting that eNAMPT is an indispensable permissive agent for myeloproliferation of MPN-associated myelofibrosis. The lack of correlation between eNAMPT and hs-CRP revealed that eNAMPT in MPN-associated myelofibrosis does not behave as a canonical inflammatory cytokine. In addition, higher levels of eNAMPT predicted longer time to blast transformation, and protected against progression toward thrombocytopenia and large splenomegaly. In conclusion, in MPN-associated myelofibrosis high levels of eNAMPT mark the myeloproliferative potential and, at variance with a high number of cancers, are protective against disease progression. Am. J. Hematol. 91:709-713, 2016. © 2016 Wiley Periodicals, Inc.

Physiological and pathophysiological roles of NAMPT and NAD metabolism

Nicotinamide phosphoribosyltransferase (NAMPT) is a regulator of the intracellular nicotinamide adenine dinucleotide (NAD) pool. NAD is an essential coenzyme involved in cellular redox reactions and is a substrate for NAD-dependent enzymes. In various metabolic disorders and during ageing, levels of NAD are decreased. Through its NAD-biosynthetic activity, NAMPT influences the activity of NAD-dependent enzymes, thereby regulating cellular metabolism. In addition to its enzymatic function, extracellular NAMPT (eNAMPT) has cytokine-like activity. Abnormal levels of eNAMPT are associated with various metabolic disorders. NAMPT is able to modulate processes involved in the pathogenesis of obesity and related disorders such as nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) by influencing the oxidative stress response, apoptosis, lipid and glucose metabolism, inflammation and insulin resistance. NAMPT also has a crucial role in cancer cell metabolism, is often overexpressed in tumour tissues and is an experimental target for antitumour therapies. In this Review, we discuss current understanding of the functions of NAMPT and highlight progress made in identifying the physiological role of NAMPT and its relevance in various human diseases and conditions, such as obesity, NAFLD, T2DM, cancer and ageing.

Interleukin-17A Gene Expression in Morbidly Obese Women

Data from recent studies conducted in rodent models and humans suggest that interleukin-17A (IL-17A) plays a role in the induction of inflammation in adipose tissue during obesity. The aim of this study was to assess the gene expression of IL-17A in adipose tissue of morbidly obese patients. We used RT-PCR to evaluate the expression of IL-17A and several adipo/cytokines in the visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) of 10 normal-weight control women (BMI < 25 kg/m²) and 30 morbidly obese women (MO, BMI > 40 kg/m²). We measured serum levels of IL-17A and adipo/cytokines in MO and normal weight women. IL-17A expression was significantly higher in VAT than in SAT in MO patients (p = 0.0127). It was very low in normal-weight controls in both VAT and SAT tissues. We found positive correlations between IL-17A and IL-6, lipocalin-2 and resistin in VAT of MO patients. The circulating level of IL-17A was higher in the normal-weight group than the MO patients (p = 0.032), and it was significantly related to adiponectin and TNFRII levels. In conclusion, IL-17A expression in VAT is increased in morbidly obese women, which suggests a link between obesity and innate immunity in low-grade chronic inflammation in morbidly obese women.

Serum visfatin concentration in acutely ill and weight-recovered patients with anorexia nervosa

Visfatin is a recently described protein that is thought to regulate the process of adipocyte differentiation. Findings suggest that visfatin may be actively involved in the control of weight regulatory networks. However, to what extent and which role it plays in eating disorders is still poorly understood, as mixed results have been reported. The aim of the current study was to investigate serum visfatin concentrations on a cross sectional sample between acute anorexia nervosa patients (n=44), weight recovered patients (n=13) and healthy controls (n=46) and a longitudinal sample of acute patients (n=57) during weight recovery at three different time-points. Results did not show significant differences in visfatin between the three groups; however, acute patients showed a higher visfatin/BMI-SDS ratio than controls and recovered patients. Longitudinal results revealed an increase of visfatin levels during therapy. Our results suggest that high ratios of visfatin/BMI-SDS could be a state marker in acute anorexia nervosa, displaying a compensatory mechanism of the individual to maintain normal visfatin levels under malnourished conditions.

Interactions between adiponectin, visfatin, and omentin in subcutaneous and visceral adipose tissues and serum, and correlations with clinical and peripheral metabolic factors

Adiponectin, visfatin, and omentin are adipokines involved in insulin sensitivity. This study aimed to determine interactions between these adipokines in subcutaneous and visceral fat and in serum, and their associations with clinical factors. Adiponectin was present at the highest levels in subcutaneous and visceral fat and serum. Subcutaneous adiponectin showed positive correlations with serum adiponectin and the quantitative insulin sensitivity check index (QUICKI). Serum adiponectin correlated positively with QUICKI and serum omentin-1 but negatively with body weight, BMI, and homeostasis model assessment of insulin resistance (HOMA-IR). Subcutaneous omentin correlated positively with QUICKI but negatively with waist and hip circumferences. Serum omentin-1 correlated positively with QUICKI but negatively with body weight, BMI, waist and hip circumferences, weight gain, and HOMA-IR. Serum visfatin correlated positively with serum omentin-1 and negatively with weight gain. Serum peptide YY (PYY) levels were correlated positively with subcutaneous visfatin but negatively with visceral visfatin. Positive correlations were observed between subcutaneous expression of adiponectin, visfatin, and omentin and visceral expression of these genes. Multiple linear regression analysis showed that serum adiponectin was associated with BMI and QUICKI. Serum omentin-1 could be predicted from BMI, QUICKI, and weight gain. Weight gain, serum adiponectin, omentin-1, and DBP could be used to predict serum visfatin. In conclusion, adiponectin and omentin from subcutaneous fat displayed correlations with decreased obesity and increased insulin sensitivity while visfatin showed an association with serum PYY and weight gain. The expressions of these adipokines were correlated within each type of fat but not between different fat depots.

Adipose tissue as an endocrine organ

Obesity is one of the most important health challenges faced by developed countries and is increasingly affecting adolescents and children. Obesity is also a considerable risk factor for the development of numerous other chronic diseases, such as insulin resistance, type 2 diabetes, heart disease and nonalcoholic fatty liver disease. The epidemic proportions of obesity and its numerous comorbidities are bringing into focus the highly complex and metabolically active adipose tissue. Adipose tissue is increasingly being considered as a functional endocrine organ. This article discusses the endocrine effects of adipose tissue during obesity and the systemic impact of this signaling.

Clinical and adipocytokine changes after bariatric surgery in morbidly obese women

OBJECTIVE

Recent studies report the effect of bariatric surgery on glycaemia control and prevention of type-2-diabetes in obese patients. This study is about the pathophysiological mechanisms associated to these changes.

DESIGN AND METHODS

Circulating levels of receptors of tumor necrosis factor (TNF-RI, TNF-RII), visfatin, high molecular weight (HMW) adiponectin, and C reactive protein (CRP) in 30 morbidly obese women (body mass index, BMI>40 kg/m(2) ) and 60 normal-weight controls (BMI>25 kg/m(2) ) were analyzed. Morbidly obese were studied at three time-points: before surgery (baseline), and 6 and 12 months after.

RESULTS

After surgery, the levels of TNF-RI, TNF-RII, visfatin, and CRP were significantly lower than its baseline levels, whereas HMW adiponectin was higher. Fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA2-IR) levels were markedly lower postoperatively. High density lipoproteins (HDL) moderately increased, and triglyceride levels had sharply decreased. The study of the predictive value of variables indicated that preoperative levels of TNF-RI and visfatin correlated positively with levels of glucose, insulin, glycosylated hemoglobin A1c, and HOMA2-IR postoperatively, whereas adiponectin levels correlated negatively. Baseline CRP levels negatively linked to HDL and TNF-RII positively to triglyceride.

CONCLUSIONS

The preoperative profile with high levels of proinflammatory adipocytokines is linked to smaller improvements in glucose homeostasis and lipid factors. The use of a range of biomarkers may predict the level of metabolic changes following bariatric surgery.

DISORDER OF INTERCELLULAR CORRELATIONS IN PATHOGENESIS OF FATTY TISSUE INFLAMMATION IN METABOLIC SYNDROME

Due to the fact that nowadays mechanisms of syntropy of pathological conditions and nosological units, united within the metabolic syndrome, remain unclear, the scientific review attempts to summarize data on the role of fatty tissue inflammation in pathogenesis of this symptom complex. The results of recent major foreign studies on evaluation of pro-inflammatory activity of adipocytes and macrophages of the fatty tissue, as well as the data on peculiarities of their interactions in abdominal obesity, which is the main component of the metabolic syndrome, were analyzed. Studing pathogenesis of fatty tissue inflammation from the perspective of evaluation of disorders in cell cooperation will allow to more deeply understand cellular and molecular mechanisms of this process as well as open new avenues for developing new pathogenetically justified approaches to metabolic syndrome treatment.

Portal and systemic levels of visfatin in morbidly obese subjects undergoing bariatric surgery

The aim of the present study was to compare the levels of visfatin in portal and systemic circulations and to assess the possible relationship of visfatin with systemic inflammation and insulin resistance in morbidly obese patients undergoing bariatric surgery. A total of 46 morbidly obese patients (BMI = 45.3 ± 5.3 kg/m(2)) undergoing bariatric surgery were included in this study. Blood samplings were performed simultaneously from portal and systemic veins during surgery. Visfatin was measured in both portal and systemic venous samples. Besides, fasting serum levels of insulin, glucose, lipid profile, visfatin, and hs-CRP were determined in systemic venous blood samples. Insulin sensitivity was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Visfatin concentrations were significantly higher in portal vein than systemic veins (11.9 ± 12.1 vs. 5.1 ± 3.3 ng/ml, p < 0.0001). While systemic levels of visfatin were significantly correlated with circulating levels of hs-CRP (r = 0.527, p < 0.0001), there were no significant correlations between portal levels of visfatin with systemic levels of hs-CRP concentrations. Substantially higher levels of visfatin in portal vein than systemic veins provide evidence that visceral adipose tissue is the major secretory source of visfatin in humans. Our findings underscore that visceral adipose tissue is an active endocrine organ that is involved in the complex interrelationship between obesity and pathologic conditions.

Plasma visfatin levels and gene expression in morbidly obese women with associated fatty liver disease

OBJECTIVES

The few studies on the physiopathological role of visfatin in morbid obesity and the related metabolic diseases have led us to examine visfatin levels and its liver gene expression in morbidly obese women with non-alcoholic fatty liver disease (NAFLD).

DESIGN AND METHODS

We examined the circulating levels of visfatin by ELISA in serum samples from 95 morbidly obese women (MO) (BMI>40 kg/m(2)) who underwent bariatric surgery and 38 normal weight control women (BMI<25 kg/m(2)). We analysed visfatin liver and adipose tissue mRNA expression by RT-PCR. We evaluated the circulating levels and gene expression of adiponectin, resistin, RBP4, TNFα, IL6 and CRP.

RESULTS

Serum visfatin was significantly higher in MO compared with controls, and also in MO with NAFLD was significantly higher than MO with normal liver. We found that NAFLD diabetic patients presented similar serum visfatin levels than non-diabetic. Serum visfatin correlated with IL6 (r=0.496; p<0.001) and CRP levels (r=0.241; p=0.049). Liver visfatin expression was significantly higher in MO compared to controls and was also significantly higher in MO with NAFLD than in MO with normal liver. Visfatin liver expression correlated positively with resistin (r=0.436, p=0.018) and TNFα expression (r=0.328, p=0.028). Visfatin expression in adipose tissues was similar among the MO groups analysed.

CONCLUSION

Serum visfatin and its liver expression are higher in MO women with NAFLD, irrespective of the presence of diabetes. Serum visfatin and its liver expression correlate positively with pro-inflammatory factors. These findings suggest that visfatin may be a molecule related with fat inflammation in morbid obesity and fatty liver disease.